MAN: HIS GEOLOGICAL RELATIONS. 119 



left traces of his presence in the relics of his rude 

 feasts, and in his lost or cast-away weapons. These 

 remains being found partly on the surface, partly im- 

 bedded in the soil, and partly covered over by sands, 

 gravels, peat-mosses, lake-sUts, cave-earths, and other 

 superficial accumulations, belong to the domains of 

 archseology and geology — to archaeology so far as the 

 determination of the race who left them is concerned, 

 and to geology for an approximation to their relative 

 antiquity. We say, relative antiquity, for geology, 

 carrying the investigation beyond the limits of history, 

 can assign no dates in years and centuries, but 

 simply state the relations in time that one event 

 bears to another event. Thus, the remains of an 

 animal found at two feet under the surface of a peat- 

 moss must be much more recent, considering the 

 slow growth of peat, than those of another animal 

 occurring at the depth of twenty feet ; but as there is 

 no determined ratio for the growth of peat, the geo- 

 logist cannot afiix a date to either relic, nor say how 

 much in years the entombment of the one preceded 

 the entombment of the other. Again, an animal like 

 the great Irish deer, unnoticed in history, must be 

 regarded as prehistoric and of high antiquity, and 

 any human remains found in unmistakable connection 

 with its bones, must be considered as contempora- 

 neous. But, as we have no assignable chronology 



